Any suggestion for printing PA6-CF on A1

[user_3268691422]

Got me a roll of Polymaker PA6-CF20 to experiment with, and I think I need a bit of help. I configured everything using the parameters provided by Polymaker, but the prints are literally melting when it gets to small areas - almost like the heat from the nozzle staying so close is melting the print in the immediate area.

Initially I tried just printing a small cone, and as you can see below it starts out great but when it gets to the top it turns into volcano instead, complete with lava flowing down the side.

I then compared the settings that Polymaker provides with what Bambu provides and found some remarkable differences. For instance Polymaker says the plate should be 25-50, whereas Bambu says it should be 100. Even more odd is that Polymaker says all fans must be off for the entire print, but Bambu only wants the fans off for the first 3 layers.

So, I tried morphing a bit toward the Bambu settings and the quality improved slightly. Eventually I made it all the way to the Bambu defaults for their own PA6-CF and got the best print so far with the Polymaker filament. Now my cone looks like this:

Just to get a bit more to judge from I also printed a benchy using Bambu’s setting on the Polymaker, and with the exception of the smoke stack it’s far and away the most awesome benchy I’ve ever printed. But just like everything else, once it gets to a small thing (the smoke stack) it wants to melt.

I would very much appreciate any suggestions anyone may have. The filament has been dried using a Sunlu S4 and the A1 has been placed in an area to ensure no drafts, with an ambient temperature around 75F. Polymaker does specifically state that no enclosure is needed, only a draft-free area.

[Lenyo]

Well, I think its not supported so there is that, but you may be disproving that although I would wonder about wear on certain parts of your system.

That being said I think you might want to try filament settings>cooling tab>min layer time / slow printing for better layer cooling on. By setting these to a higher timeframe fast layers will be slowed down.

[user_3268691422]

Thanks for the suggestion. The setting labeled “slow printing down for better layer cooling” in the filament>cooling tab is enabled already. But I’ll test further slowing of those small layers by adding a modifier so I can let those layers cool down even more. I have no doubt it’s going to come down to something like that, where too much heat is effecting those small parts of the print

According to the Bambu Wiki, PA-CF is supported on the A1.

What Filaments Can A1 Print?

Low-temperature filaments such as PLA, PETG, TPU, and support materials for PLA and PETG (Support for PLA, PVA, HIPS, etc.).

Conventional high-temperature filaments such as ABS, ASA, PC, PA, PA-CF/GF, PET-CF/GF, PPA-CF/GF, etc…

Of course that’s what the printer can actually print and does not take into consideration toxic fumes, so some of the things that it can physically print are just not safe to do so. And then some of them may have layer adhesion issues without the heat of an enclosure.

I’m using a hardened nozzle, external spool without the AMS Lite and the A1 extruder gear is already hardened steel, so what other than the PTFE tube would have a potential abnormal wear issue?

[EnoTheThracian]

Print two at the same time time or enforce a prime tower. That will give more time for cooling. Min Layer time can in fact be counterproductive as it merely slows down the print. In that way, the hot nozzle heats the part even more.

[movingimage]

You may need some fan for small detail layers - even though it is a filament that generally doesn’t “like” fan.

[user_3268691422]

Got some pretty good improvements now. Using a prime tower or forced cooling either one helps tremendously. The prime tower works just a bit better, but for most cases I foresee either works adequately so when looks aren’t quite as important the extra filament could be saved - and when looks matter that much the extra filament isn’t really an issue.

Here’s my same cone printed with a prime tower:

And here it is with forced cooling:

Either could be cleaned up easily at the tip and neither has any of the melty collapsing I was getting before.

And here’s my new benchy:

I consider all these to be good enough (actually better than good enough and better than I expected), so Polymaker PA6-CF20 is now one of my go-to filaments and a whole new realm of printing options has just poofed into existence for me.

Thanks to everyone for your suggestions and help with this. It is much appreciated. By the way, the level of forced cooling was far more than I would have ever expected - 100% part fan for the top 20% of the cone and for the entire smoke stack on the benchy.

[elsikander]

Hi, just to clarify, the filament settings you ended up using are Bambu’s PA-CF?

Your fan settings were default for the everything other than the smokestack on the benchy?

What size nozzle?

[PrinterMcgee]

Well you’ve definitely proven it’s possible. Bambu is putting out contradictory info, unless I’m reading it wrong. You’re correct, the wiki does make it look like it’s ok but on the store page it says “not recommended”?

[user_3268691422]

Yes, I got the best results using the default settings for Bambu brand PA6-CF. The only change was the fan, and I did increase the fan to100% on the top of the cone and on the entire smokestack of the benchy, but nowhere else. The fan definitely needs to go up on small areas, but exactly how small those areas can get is probably more a guess than anything else. On the Benchy it was easy as the smokestack is a drastic change so it’s clear where to change the fan. On the cone I simply had to watch the entire thing and as soon as I saw it turn just the tiniest bit glossy I manually increased the fan (that was about 80% of the layers in, not 80% total progress).

I used the 0.4 hardened steel nozzle for all of those prints.

[user_3268691422]

Yeah, that “not recommended” may be the culmination of a few different things. You do have to upgrade the nozzle to hardened steel as the default for the A1 is stainless. Bambu also says their own brand of PA6 has to be used in an enclosure, whereas Polymaker says the opposite and that all of their nylon should be done open and at room temperature. In the wiki Bambu also does clarify that large models may not work well on the A1 as they may warp because of temperature variations as the model prints.

But you can also find other contradictions from the sheet you posted. For example, Bambu sells hardened nozzles for the A1 series and includes some of the otherwise forbidden materials in the list that requires those nozzles (and the list includes PA as “optional” and “CF/GF filaments from other brands” as “required”). So on an entire line of nozzles that only work on the A1, they say “required” for the filament I used rather than “not applicable”.

[elsikander]

Is your filament branded Fiberon (by Polymaker)? It seems they previously branded it differently. I have a spool of this and the hardened steel .4 nozzle, so your post has me convinced to try it without enclosure on A1. Did you set the speed to 50% or change any speed settings?

Did you have to pre-dry and print from dry box?

[user_3268691422]

My spool is the old branding (Polymide) on the plain cardboard spool. It’s been rebranded to Fiberon and put on a black cardboard spool. Supposedly the product is exactly the same with the exception of a possible very minor color difference. All of the technical data is unchanged between the two.

I did not slow the printing down and let it go at the default for Bambu PA6-CF. It does slow by default a bit on layers that print fast to allow it more time to cool, but I found that any additional slowing only caused it to ‘melt’ more because the hot nozzle was staying too close for too long. It even melts at default on extremely quick layers, which is the problem that I overcame by adding 100% fan. You can also print a purge tower to move the nozzle away after each layer and let the tiny layers cool that way (but then you have a much more noticeable seam). If your print has no layers that get that small and print that fast (like the smokestack on the benchy) you won’t need to worry about extra fan at all.

As far as printing it without an enclosure, Polymaker calls for printing it at room temperature. If you have an enclosed printer they say you should leave it open during printing to keep the ambient temperature from going up. This applies to all of their nylon products.

I did dry it, but I don’t know if it was necessary or not. I printed from a new, unopened package. As a rule, I always dry new spools just to be on the safe side. I’ve dried it as well for all of my subsequent uses, but again I do that with everything but PLA. During printing I put it on the external spool holder and did not print straight from the dryer. It is not compatible with the AMS lite, as the AMS lite does not have hardened gears, so it would likely just chew the gears up in no time at all. The A1 extruder does have hardened gears so there’s no worry there.

Aside from the testing I’ve printed a very few functional parts, but nothing with the required detail of a benchy. I’ve had no issues at all with printing those simpler-type items. No extra fan needed or anything, and tolerance has been impeccable on things like screw holes and such.

I print on either a Bambu smooth PEI plate or a Wham Bam carbon fiber plate. This stuff adheres very well and is almost intimidating when removing it - almost making you think you’re going to damage the plate getting it off. That said, I use a lot of glue with it and would recommend the same to anyone using it to ensure that you have a good release barrier in place.

My suggestion to you would be to give it a try. Do a test print with something small and see how it does for you, then you’re not out a lot if it doesn’t work out. Personally, I’m beyond glad that I tried it. It took me somewhere around 100g for experimenting, but I started at the completely wrong end so I used a lot more than would have been necessary for a bit of fine tuning had I started closer to where I ended. But even so it gives me the ability to print for more real-world usable things than I ever expected I’d be able to do with an A1. And an A1 is all I have, so had I never tried this many things would still be out of reach to me.

[elsikander]

Another question, you didn’t change out the extruder gear? I didn’t know the A1 already has a hardened steel gear assembly.

[user_3268691422]

@elsikander

you didn’t change out the extruder gear?

No, the A1 comes with hardened extruder gears.

[elsikander]

So I ran a benchie using your experience as a guide. Dried filament for 24 hours at 70C, using the same filament (other than being branded Fiberon), put it on external spool rack, changed nozzle to hardened steel 0.4. However, no glue on plate. Ran benchie, it started fine then turned into a spaghetti mess.

Then I got some magigoo and applied it to a clean plate. Ran benchie again (this was around 8 hours later) and got a perfect print. I didn’t change the fan speed for the smokestack. I just used the Bamba PA-CF filament setting in my slicer (Orca) as you advised. No change to heat settings (it’s printing at 270). No change to speed settings (printing at 100% speed).

I wonder if the success is due to hitting a moisture level sweet spot with it sitting out 8 hours? Or if it’s because I got it nice and fully dried to start with? I don’t know. The filament itself was very brittle after drying. Since it was already loaded, I didn’t bother to take it out to feel for a difference in brittle-ness for the second attempt. The moisture curve, per Polymakers data sheet, shows a fast initial gain, but I have doubts that I would have really gained much in 8 hours. I’m continuing printing with the spool fully exposed to see how it changes over the next day or two.

[elsikander]

Started another larger print last night, layer height 0.12mm, set nozzle temp to 290C, right after the brims were laid I lowered plate temp way down to 35C (the default far exceeded the recommended range), speed mode to quiet. This morning it looks great, and I don’t see any stringiness that’s supposed to happen with excess moisture. I live in the humid south, RH inside house is 55-60. It seems this material is quite forgiving but I’m waiting for the print to finish for final judgment. 12 hours to go.

[Stormcrow]

Do you have anything to add here yet? I am researching print PA6-GF on my A1.

[ahoeveler]

I’m bookmarking this! I too had seen that the PA6-CF seemed to be supported with the hardened steel nozzles, and picked up a roll along with my A1 last year. But I haven’t yet cracked the seal on the spool of Bambu Lab PA6-CF.
One suggestion based on something else I saw here was the… “z-hop?” setting? I’m sorry I don’t know more but it was a setting that bumps the hot nozzle away from small areas like you’re describing. I’ll see if I can find the post.

[elsikander]

After experimenting with a few rolls, I don’t advise to print with it unless it’s very dry, and keep it dry the whole time for best results.

It prints fine on the A1, but support removal is difficult with the default support interface settings. I never really dialed in better settings. It picks up water from RH fairly quickly and this makes clean support removal even more difficult. Another reason to dry it and keep it dry.

In any case, I’m taking a liking to PET-CF right now. It’s a bit more forgiving to print with, cheaper, and is much less susceptible to moisture.